Hierarchical Control for Isolated Microgrid Clusters Under Renewable Variability

Abstract

This paper presents a novel hierarchical control foramicrogridcluster (MGC) operating in islanded mode,integrating renewable energy technologies (RETs), energystorage systems (ESSs), and variable demands. The controlstrategy dynamically manages power distribution by introducingthe real-time available power concept, enabling proportionalallocation of power among microgrids (MGs) based on theiroperational capacity.The proposed configuration includes MGswith grid-forming (GFM) inverters for voltage and frequencycontrol andMGs with grid-following(GFL)inverter for powercontrol.Unlike conventional methods that oversimplify thedynamics of RETs and ESSs, this approach ensures adaptive andreliable power sharing while addressing the challenges ofintermittency and demand variability.Time-domain simulationsacross various operating scenarios validate the effectiveness ofthe proposed strategy, demonstrating its ability to maintain stablevoltage and frequency in isolated MGCs. The results confirm therobustness and adaptability of theproposedhierarchical controlframework, making it a viable solution for improving operationalreliability and resilience in high-RETspenetration systems. Thisinnovative approach advances the state of the art by providing adynamic solution to manage the complexities of islanded MGCoperations.